package com.king.filter;

import com.alibaba.fastjson.JSON;
import com.king.model.entity.RestResponse;
import com.king.utils.BaseContextUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.AntPathMatcher;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@WebFilter(filterName = "loginCheckFilter", urlPatterns = "/*")
@Slf4j
public class LoginCheckFilter implements Filter {
    //路径匹配器，支持通配符
    public static final AntPathMatcher PATH_MATCHER = new AntPathMatcher();

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest) servletRequest;
        HttpServletResponse response = (HttpServletResponse) servletResponse;
        /**
         1、获取本次请求的URI
         2、判断本次请求是否需要处理
         3、如果不需要处理，则直接放行
         4、判断登录状态，如果已登录，则直接放行
         5、如果未登录则返回未登录结果
         */
        //1、获取本次请求的URI
        String requestURI = request.getRequestURI();
        log.info("拦截到请求：{}", requestURI);
        String[] urls = new String[]{
                "/chat/login",
                "/chat/register",
                "/chat/forgetPassword",
                "/chat/logout"
        };
        //2、判断本次请求是否需要处理
        boolean check = check(urls, requestURI);
        //3、如果不需要处理，则直接放行
        if (check) {
            log.info("本次请求{}不需要处理", requestURI);
            filterChain.doFilter(request, response);
            return;
        }
        // 4、判断登录状态，如果已登录，则直接放行
        if (request.getSession().getAttribute("netty-chat-user") != null) {
            log.info("用户已登录，用户id为：{}", request.getSession().getAttribute("netty-chat-user"));
            //将用户id设置到当前线程中
            Long userId = (Long) request.getSession().getAttribute("netty-chat-user");
            BaseContextUtils.setCurrentId(userId);
            filterChain.doFilter(request, response);
            return;
        }
        log.info("用户未登录");
        //5、如果未登录则返回未登录结果,通过输出流方式向客户端页面响应数据
        response.getWriter().write(JSON.toJSONString(RestResponse.fail("NOTLOGIN")));
        return;
    }

    /**
     * 路径匹配，检查本次请求是否放行
     *
     * @param urls
     * @param requestURI
     * @return
     */
    public boolean check(String[] urls, String requestURI) {
        for (String url : urls) {
            boolean match = PATH_MATCHER.match(url, requestURI);
            if (match) {
                return true;
            }
        }
        return false;
    }
}
